Question

Evaluate fog and gof if f(x)=5x-8 and g(x)= x^3

Answer 1

see explanation

Explanation:

note that f ○ g = f(g(x))

To evaluate substitute x = x³ into f(x)

f(g(x)) = f(x³) = 5x³ - 8

In the same way

g ○ f = g(f(x))

To evaluate substitute x = 5x - 8 into g(x)

g(f(x)) = g(5x - 8) = (5x - 8)³